<?php
///session_start();
class yzm
{
 
 function createRandomStr($strLen)
 {
  list($usec, $sec) = explode(' ', microtime());
        (float) $sec + ((float) $usec * 100000);
        
  $number = '';
  $number_len = $strLen;
  $stuff = '1234567890abcdefghijklmnopqrstuvwxyz';//��������ʾ��ΧABCDEFGHIJKLMNOPQRSTUVWXYZ
  $stuff_len = strlen($stuff) - 1;
  for ($i = 0; $i < $number_len; $i++) {
  $number .= substr($stuff, mt_rand(0, $stuff_len), 1);
  }
  return $number;
 }
}
?>